Hilton celebrated Earth Hour (March 25) – the worldwide movement for the planet organized by the World Wildlife Fund – with the launch of a global social media contest.

Building on the core theme of Earth Hour – turning off the lights for an hour to save energy – contestants are invited to submit a photo and caption showing how they celebrated the event. The grand prize includes travel and accommodation, including a five-night stay at the Canopy by Hilton Reykjavik City Centre in Iceland.

Submissions must include #EarthHour and #TravelwithPurposeContest when posting. Official contest rules are available at http://bit.ly/2n9KLay.

The contest closes on April 1, with the winner being announced on Earth Day, April 22.